cheap SPL meter for subwoofers

Lope · 14th July 2009, 01:21 PM

I've done some reading on the WM-61A.

The problem is most preamp schematics suggested for it for it are only good til 110dB or 118dB.
How do you measure louder signals?

What is the simplest way to measure relative SPL dB?

For example, measuring the SPL of a speaker at 40hz, then measuring the SPL at 50hz. If one is x the other is y, I just want to know for example, y is 5dB more than x. or the 40hz signal is 80dB above my silence measurement.

So I'm thinking I just need a linear mic like the panasonic WM-61A and a computer with speakerworkshop running on it? or some RTA?
Then possibly a preamp?

Ron E · 16th July 2009, 03:51 AM

Radio Shack (Tandy in some parts of the world) has an inexpensive meter if you want to measure actual SPL.

A measurement system like speaker workshop is not meant for measuring high SPL. In order to do that, you need a SPL meter.

You can make an SPL meter, but probably not for what the shack sells them for.

Lope · 16th July 2009, 01:25 PM

the radioshack one can't do below 60hz though.
the WM-61A can do 134dB apparently, which would be pleanty for a SPL meter. i just need a means of measuring it. I could even use an oscilloscope maybe.

adason · 16th July 2009, 05:39 PM

here is usefull info how to midify radio shack to be more accurate fo low frequencies:
http://forum.audiogon.com/cgi-bin/fr...6&openfrom&3&4

GM · 16th July 2009, 08:09 PM

I imagine this info is from Eric Wallin's extensive work on the various RS meters, so there may be some more info here: http://mysite.verizon.net/tammie_eric/audio/audio.html

Also: http://www.hometheatershack.com/foru...n-results.html

GM

danielm · 19th July 2009, 06:03 PM

How about making the measurment at 10m and adding the 10db loss?
That's how I do it using the rat shack.

danielm · 19th July 2009, 07:35 PM

Oops... make that 20db for 10m vs 1m.

14th July 2009, 01:21 PM	#1
Lope diyAudio Member Join Date: Jul 2009	cheap SPL meter for subwoofers I've done some reading on the WM-61A. The problem is most preamp schematics suggested for it for it are only good til 110dB or 118dB. How do you measure louder signals? What is the simplest way to measure relative SPL dB? For example, measuring the SPL of a speaker at 40hz, then measuring the SPL at 50hz. If one is x the other is y, I just want to know for example, y is 5dB more than x. or the 40hz signal is 80dB above my silence measurement. So I'm thinking I just need a linear mic like the panasonic WM-61A and a computer with speakerworkshop running on it? or some RTA? Then possibly a preamp?

16th July 2009, 03:51 AM	#2
Ron E diyAudio Member Join Date: Jun 2002 Location: USA, MN	Radio Shack (Tandy in some parts of the world) has an inexpensive meter if you want to measure actual SPL. A measurement system like speaker workshop is not meant for measuring high SPL. In order to do that, you need a SPL meter. You can make an SPL meter, but probably not for what the shack sells them for. __________________ Our species needs, and deserves, a citizenry with minds wide awake and a basic understanding of how the world works. --Carl Sagan Science is a way of thinking much more than it is a body of knowledge. --Carl Sagan

16th July 2009, 08:09 PM	#5
GM diyAudio Member Join Date: Jun 2003 Location: Chamblee, Ga.	I imagine this info is from Eric Wallin's extensive work on the various RS meters, so there may be some more info here: http://mysite.verizon.net/tammie_eric/audio/audio.html Also: http://www.hometheatershack.com/foru...n-results.html GM __________________ Loud is Beautiful if it's Clean! As always though, the usual disclaimers apply to this post's contents.

Thread Tools	Search this Thread
Show Printable Version Email this Page	Search this Thread: Advanced Search

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
how to make this esr meter work with 250uA Panel meter	dytln_02	Everything Else	2	27th January 2007 11:13 PM
Scosche SPL meter: Cheap find with potential, or cheap junk?	theAnonymous1	Everything Else	5	11th October 2006 04:40 AM
inductance meter from a cheap meter?	jarthel	Parts	3	22nd September 2006 06:37 AM
Cheap autoranging meter	Jean	Parts	1	21st July 2002 03:42 AM


	Please consider donating to help us continue to serve you. Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving

16th July 2009, 01:25 PM	#3
Lope diyAudio Member Join Date: Jul 2009	the radioshack one can't do below 60hz though. the WM-61A can do 134dB apparently, which would be pleanty for a SPL meter. i just need a means of measuring it. I could even use an oscilloscope maybe.

16th July 2009, 05:39 PM	#4
adason diyAudio Member Join Date: Nov 2004 Location: home sweet home	here is usefull info how to midify radio shack to be more accurate fo low frequencies: http://forum.audiogon.com/cgi-bin/fr...6&openfrom&3&4

19th July 2009, 06:03 PM	#6
danielm diyAudio Member Join Date: Dec 2006	How about making the measurment at 10m and adding the 10db loss? That's how I do it using the rat shack.

19th July 2009, 07:35 PM	#7
danielm diyAudio Member Join Date: Dec 2006	Oops... make that 20db for 10m vs 1m.

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)

New To Site?	Need Help?
Register to Participate Search Privacy Statement Contact Us	Frequently Asked Questions Did you forget your password? Mark Forums Read